[IgG4-related disease]

The IgG4-related systemic disease as well as the homonymous variant IgG4-related orbital disease were first described less than 15 years ago. The mostly subacute clinical symptoms can be multifarious and the classical case is characterized by an orbital inflammatory condition with a bilateral enlargement of the lacrimal glands; however, any other orbital tissue with the exception of the eyeball can be affected by the lymphocytic inflammatory infiltration.

Based on the current literature the clinical picture, epidemiology, pathogenesis and treatment options are described. A focus is on the differential diagnostic demarcation from other inflammatory processes of the orbit.

The IgG4-related orbital disease is an important differential diagnosis of inflammatory diseases of the orbit. The condition can exhibit considerable clinical and imaging similarity to idiopathic inflammation of the orbit, to the specific inflammations seen in systemic diseases, to Graves' orbitopathy and to lymphoproliferative diseases and lymphoma. After histopathologic confirmation the interdisciplinary clarification and treatment consensus are indispensable.